Hello, Had a quick look into uBLAS library, and noted the incompatibility between std::vector<> and ublas' binary operations. For example, I have an ublas::matrix<> and wanted to multiply it by a std::vector<>. Since _all_ of ublas data containers provide iterators, I'm wondering why the library doesn't provide algorithms that work on iterators? In this way data structures and operators will be decoupled. For example, to do the product between a matrix and a vector: ********* untested code ********* template <class MatrixRowIterator, class MatrixColIterator, class InputIterator, class OutputIterator> OutputIterator prod(MatrixRowIterator first_row, MatrixRowIterator last_row, MatrixColIterator, InputIterator first_vec, OutputIterator result) { InputIterator cp_first=first_vec; while(first_row!=last_row) { typename MatrixRowIterator::value_type val(0); MatrixColIterator first_col, last_col; first_col=first_row.begin(); last_col=first_row.end(); while(first_col!=last_col) val+= *first_col++ * *first_vec++; *result++ = val; ++first_row; first_vec=cp_first; } return result; } // user side : prod(umatrix.begin1(), umatrix.end1(), umatrix.begin2(), std_vector.begin(), std::back_inserter(std_vector_result)); This of course with the respective preconditions. Also, wouldn't be a good idea to provide copy c'tor and operators accepting std::vector<> for the ublas::vector<> ? Regards, -- vladimir josef sykora morphochem AG gmunder str. 37-37a 81379 muenchen tel. ++49-89-78005-0 fax ++49-89-78005-555 vladimir.sykora@morphochem.de http://www.morphochem.de